Touch technologies are commonly used as input devices for a variety of products. The usage of touch devices of various kinds is growing sharply due to the emergence of new mobile devices such as Personal Digital Assists (PDA), tablet PCs and wireless flat panel display (FPD) screen displays. These new devices are usually not connected to standard keyboards, mice or like input devices, which are deemed to limit their mobility. Instead there is a tendency to use touch input technologies of one kind or another. A stylus and/or fingertip may be used as a user interaction.
U.S. Pat. No. 6,690,156 entitled “Physical Object Location Apparatus and Method and a Platform using the same” and US Patent Publication No. 20040095333 entitled “Transparent Digitizer” both of which are assigned to N-trig Ltd., the contents of both which are incorporated herein by reference, describe an electro-magnetic method for locating physical objects on a FPD and a transparent digitizer that can be incorporated into an electronic device, typically over the active display screen. The digitizer sensor includes a matrix of vertical and horizontal conducting lines and sensors to sense an electric signal. Positioning the physical object at a specific location on the digitizer provokes a signal whose position of origin may be detected.
U.S. Patent Application Publication No. 20040155871 entitled “Touch Detection for a Digitizer” assigned to N-trig Ltd, which is incorporated herein by reference in its entirety, describes a digitizing tablet system capable of detecting position of both physical objects and fingertip touch using the same sensing conductive lines. Typically, the system includes a transparent sensor overlaid on a FPD. The digitizer's sensor includes a matrix of vertical and horizontal conducting lines to sense an electric signal. Touching the digitizer in a specific location provokes a signal whose position of origin may be detected.
U.S. Patent Application Publication No. 20060012580, entitled “Automatic switching for a dual mode digitizer” assigned to N-Trig, the contents of which is incorporated herein by reference, describes a method utilizing different types of user interactions, e.g. electromagnetic stylus and touch, in a digitizer system. A method for ‘palm rejection’ based on the size of the detected area of the touch, hence distinguishing between localized touch events and wide area touch events is described.